Question

Column I and column II contains four entries each. Entries of column I are to be matched some entries of column II. One or more than one entries of column I may have the matching with the same entries of column II.

Answer 1

$\alpha -$emission results in decrease in mass no. by 4 units and decrease in atomic no. by 2 units as alpha particles are helium nuclei, ${}_2^{4}He$.
$\beta -$emission results in increase in atomic no. by one unit as beta particles have negative charge without mass. They are electrons, ${}_{-1}^{0}e$
$\gamma -$emission results in no change in atomic no. and no change mass no. as they have only energy. They do not have mass and charge.
${\beta }^{+}$ (Positron) emission results in decrease in atomic no. by one unit as positrons have positive charge without mass. They are anti particles of electrons, ${}_{+1}^0\beta$